Selfsimilar random process and chaotic behavior in serrated flow of high entropy alloys
Abstract
Here, the statistical and dynamic analyses of the serratedflow behavior in the nanoindentation of a highentropy alloy, Al_{0.5}CoCrCuFeNi, at various holding times and temperatures, are performed to reveal the hidden order associated with the seeminglyirregular intermittent flow. Two distinct types of dynamics are identified in the highentropy alloy, which are based on the chaotic timeseries, approximate entropy, fractal dimension, and Hurst exponent. The dynamic plastic behavior at both room temperature and 200 °C exhibits a positive Lyapunov exponent, suggesting that the underlying dynamics is chaotic. The fractal dimension of the indentation depth increases with the increase of temperature, and there is an inflection at the holding time of 10 s at the same temperature. A large fractal dimension suggests the concurrent nucleation of a large number of slip bands. In particular, for the indentation with the holding time of 10 s at room temperature, the slip process evolves as a selfsimilar random process with a weak negative correlation similar to a random walk.
 Authors:

 The Univ. of Tennessee, Knoxville, TN (United States)
 Zhengzhou Univ. (China)
 Univ. of Kentucky, Lexington, KY (United States)
 Argonne National Lab. (ANL), Argonne, IL (United States)
 Publication Date:
 Research Org.:
 Argonne National Lab. (ANL), Argonne, IL (United States)
 Sponsoring Org.:
 USDOE Office of Fossil Energy (FE); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22). Scientific User Facilities Division; National Science Foundation (NSF); National Natural Science Foundation of China (NNSFC); U.S. Army Research Laboratory  U.S. Army Research Office (ARO)
 OSTI Identifier:
 1341016
 Grant/Contract Number:
 AC0206CH11357
 Resource Type:
 Accepted Manuscript
 Journal Name:
 Scientific Reports
 Additional Journal Information:
 Journal Volume: 6; Journal ID: ISSN 20452322
 Publisher:
 Nature Publishing Group
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; material science; mathematics and computing
Citation Formats
Chen, Shuying, Yu, Liping, Ren, Jingli, Xie, Xie, Li, Xueping, Xu, Ying, Zhao, Guangfeng, Li, Peizhen, Yang, Fuqian, Ren, Yang, and Liaw, Peter K. Selfsimilar random process and chaotic behavior in serrated flow of high entropy alloys. United States: N. p., 2016.
Web. doi:10.1038/srep29798.
Chen, Shuying, Yu, Liping, Ren, Jingli, Xie, Xie, Li, Xueping, Xu, Ying, Zhao, Guangfeng, Li, Peizhen, Yang, Fuqian, Ren, Yang, & Liaw, Peter K. Selfsimilar random process and chaotic behavior in serrated flow of high entropy alloys. United States. doi:10.1038/srep29798.
Chen, Shuying, Yu, Liping, Ren, Jingli, Xie, Xie, Li, Xueping, Xu, Ying, Zhao, Guangfeng, Li, Peizhen, Yang, Fuqian, Ren, Yang, and Liaw, Peter K. Wed .
"Selfsimilar random process and chaotic behavior in serrated flow of high entropy alloys". United States. doi:10.1038/srep29798. https://www.osti.gov/servlets/purl/1341016.
@article{osti_1341016,
title = {Selfsimilar random process and chaotic behavior in serrated flow of high entropy alloys},
author = {Chen, Shuying and Yu, Liping and Ren, Jingli and Xie, Xie and Li, Xueping and Xu, Ying and Zhao, Guangfeng and Li, Peizhen and Yang, Fuqian and Ren, Yang and Liaw, Peter K.},
abstractNote = {Here, the statistical and dynamic analyses of the serratedflow behavior in the nanoindentation of a highentropy alloy, Al0.5CoCrCuFeNi, at various holding times and temperatures, are performed to reveal the hidden order associated with the seeminglyirregular intermittent flow. Two distinct types of dynamics are identified in the highentropy alloy, which are based on the chaotic timeseries, approximate entropy, fractal dimension, and Hurst exponent. The dynamic plastic behavior at both room temperature and 200 °C exhibits a positive Lyapunov exponent, suggesting that the underlying dynamics is chaotic. The fractal dimension of the indentation depth increases with the increase of temperature, and there is an inflection at the holding time of 10 s at the same temperature. A large fractal dimension suggests the concurrent nucleation of a large number of slip bands. In particular, for the indentation with the holding time of 10 s at room temperature, the slip process evolves as a selfsimilar random process with a weak negative correlation similar to a random walk.},
doi = {10.1038/srep29798},
journal = {Scientific Reports},
number = ,
volume = 6,
place = {United States},
year = {2016},
month = {7}
}
Web of Science